mcs/mbas/location.cs

   1 //
   2 // location.cs: Keeps track of the location of source code entity
   3 //
   4 // Author:
   5 //   Miguel de Icaza
   6 //
   7 // (C) 2001 Ximian, Inc.
   8 //
   9
  10 using System;
  11 using System.IO;
  12 using System.Collections;
  13 using System.Diagnostics.SymbolStore;
  14
  15 namespace Mono.MonoBASIC {
  16
  17         /// <summary>
  18         ///   Keeps track of the location in the program
  19         /// </summary>
  20         ///
  21         /// <remarks>
  22         ///   This uses a compact representation and a couple of auxiliary
  23         ///   structures to keep track of tokens to (file,line) mappings.
  24         ///
  25         ///   We could probably also keep track of columns by storing those
  26         ///   in 8 bits (and say, map anything after char 255 to be `255+').
  27         /// </remarks>
  28         public struct Location {
  29                 public int token;
  30
  31                 static Hashtable map;
  32                 static Hashtable sym_docs;
  33                 static ArrayList list;
  34                 static int global_count;
  35                 static int module_base;
  36
  37                 public readonly static Location Null;
  38
  39                 static Location ()
  40                 {
  41                         map = new Hashtable ();
  42                         list = new ArrayList ();
  43                         sym_docs = new Hashtable ();
  44                         global_count = 0;
  45                         module_base = 0;
  46                         Null.token = -1;
  47                 }
  48
  49                 static public void Push (string name)
  50                 {
  51                         map.Remove (global_count);
  52                         map.Add (global_count, name);
  53                         list.Add (global_count);
  54                         module_base = global_count;
  55                 }
  56
  57                 public Location (int row, int col)
  58                 {
  59                         if (row < 0 || col <  0)
  60                                 token = -1;
  61                         else {
  62                                 if (col > 255)
  63                                         col = 255;
  64                                 token = module_base + (row << 8) + col;
  65                                 if (global_count < token)
  66                                         global_count = token;
  67                         }
  68                 }
  69
  70                 public override string ToString ()
  71                 {
  72                         return Name + ": (" + Row + ")";
  73                 }
  74
  75                 /// <summary>
  76                 ///   Whether the Location is Null
  77                 /// </summary>
  78                 static public bool IsNull (Location l)
  79                 {
  80                         return l.token == -1;
  81                 }
  82
  83                 public string Name {
  84                         get {
  85                                 int best = 0;
  86
  87                                 if (token < 0)
  88                                         return "Internal";
  89
  90                                 foreach (int b in list){
  91                                         if (token > b)
  92                                                 best = b;
  93                                 }
  94                                 return (string) map [best];
  95                         }
  96                 }
  97
  98                 public int Row {
  99                         get {
 100                                 int best = 0;
 101
 102                                 if (token < 0)
 103                                         return 1;
 104
 105                                 foreach (int b in list){
 106                                         if (token > b)
 107                                                 best = b;
 108                                 }
 109                                 return (token - best) >> 8;
 110                         }
 111                 }
 112
 113                 public int Col {
 114                         get {
 115                                 int best = 0;
 116
 117                                 if (token < 0)
 118                                         return 1;
 119
 120                                 foreach (int b in list){
 121                                         if (token > b)
 122                                                 best = b;
 123                                 }
 124                                 return (token - best) & 0xFF;
 125                         }
 126                 }
 127
 128                 // The ISymbolDocumentWriter interface is used by the symbol writer to
 129                 // describe a single source file - for each source file there's exactly
 130                 // one corresponding ISymbolDocumentWriter instance.
 131                 //
 132                 // This class has an internal hash table mapping source document names
 133                 // to such ISymbolDocumentWriter instances - so there's exactly one
 134                 // instance per document.
 135                 //
 136                 // This property returns the ISymbolDocumentWriter instance which belongs
 137                 // to the location's source file.
 138                 //
 139                 // If we don't have a symbol writer, this property is always null.
 140                 public ISymbolDocumentWriter SymbolDocument {
 141                         get {
 142                                 ISymbolWriter sw = CodeGen.SymbolWriter;
 143                                 ISymbolDocumentWriter doc;
 144
 145                                 if (token < 0)
 146                                         return null;
 147
 148                                 // If we don't have a symbol writer, return null.
 149                                 if (sw == null)
 150                                         return null;
 151
 152                                 string path = Path.GetFullPath (Name);
 153
 154                                 if (sym_docs.Contains (path))
 155                                         // If we already created an ISymbolDocumentWriter
 156                                         // instance for this document, return it.
 157                                         doc = (ISymbolDocumentWriter) sym_docs [path];
 158                                 else {
 159                                         // Create a new ISymbolDocumentWriter instance and
 160                                         // store it in the hash table.
 161                                         doc = sw.DefineDocument (path, SymLanguageType.Basic,
 162                                                                  SymLanguageVendor.Microsoft,
 163                                                                  SymDocumentType.Text);
 164
 165                                         sym_docs.Add (path, doc);
 166                                 }
 167
 168                                 return doc;
 169                         }
 170                 }
 171         }
 172 }